Canine chondrosarcoma is a form of bone cancer that originates in the cartilage and is responsible for 5 to 10 percent of all bone tumors in dogs. The most common location for chondrosarcoma tumors is the nasal cavity, followed by the rib cage. This form of cancer spreads fast and treatment must be quick and aggressive as the condition can be life threatening.
Symptoms depend on the location of the tumors. In nasal cavity involvement, sneezing, difficulty breathing and a nasal discharge of pus and blood are common. Tumors in the rib area can protrude into the thorax and restrict lung usage, causing breathing difficulty. With pelvic tumors, loss of hind leg function can occur. As the cancer metastasizes into organs such as the lungs, symptoms such as shortness of breath, coughing, pain and lethargy can occur.
If your veterinarian suspects chondrosarcoma, a thorough physical and orthopedic examination is necessary. Common tests include blood tests, X-rays, CT scans and aspiration biopsies. X-rays of the chest and stomach look to see if the cancer has metastasized to other organs. Blood work checks the general health of your dog and helps the veterinarian determine the best course of treatment.
Because symptoms do not usually appear until the cancer is in advanced stages, treatment must be aggressive to reduce the risk of further spreading. In most cases, surgery is necessary to remove the tumor. Unfortunately, chemotherapy has not proven affective against chondrosarcoma. For nasal cavity tumors, rhinotomy -- an incision in the nose designed to drain pus -- and radiation therapy are the chosen treatment. In cases where the tumor is located on a limb, amputation is the recommended course of action. Regular follow-ups are necessary to look for continued tumor growth or the spread to organs.
Given that traditional chemotherapy is not effective, the prognosis for chondrosarcoma is not encouraging. Even with treatment, the National Canine Cancer Foundation reports that the survival of dogs with chondrosarcoma is 201 to 580 days after diagnosis. Once the cancer metastasizes, the majority of cases are fatal.
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